团头鲂对3种致病菌外膜蛋白(OMP)的免疫应答

Immune response of bluntnose black bream to outer membrane protein of three pathogenic bacteria

利用从柱状黄杆菌(Flavobacterium columnare)、嗜水气单胞菌(Aeromonas hydrophila)和温和气单胞菌(Aeromonas sobria)中提取的外膜蛋白(outer membrane protein,OMP)作为免疫原,注射接种团头鲂(Megalobrama amblycephala)后,通过测定受免鱼的交叉凝集抗体效价、肾脏和血液中吞噬细胞的吞噬活性和采用A.hydrophila活菌攻毒方法,比较了3种致病菌OMP对团头鲂的免疫原性。试验结果表明,从3种致病菌中提取的OMP对团头鲂均具有较强的免疫原性,受免鱼的血清中存在对3种致病菌的交叉凝集抗体,与对照鱼相比,肾脏和血液中吞噬细胞对吞噬原的吞噬活性和对A.hy-drophila活菌攻毒的相对免疫保护率(relative percent survival,RPS)明显上升。说明在3种致病菌的OMP上不同程度地存在共同保护性抗原。

Bluntnose black bream （Megalobrama amblycephala）were immunized with outer membrane protein （OMP）extracted from flavobacterium columnare ,aeromonas hydrophila and aeromonas sobria. The immunogenieity of OMP to bluntnose black bream were compared by examing the agglutinating antibody titers, cross-agglutinating antibody titers of serum, the phagocytic activity of phagocytes in the blood and head kidney, and relative percent survival（RPS） by challenging with live A.hydrophila. The experimental results showed that the agglutinating antibody titers and cross-agglutinating antibody titers of immunized bluntnose black bream were higher than the control group,and the phagocytic activity of phagocytes in the blood and head kidney of bluntnose black bream was significantly boosted and had a high level immune response. The crude LPS of three pathogenic bacteria were thought to have a common protective antigen which cause a cross-immune response to bluntnose black bream.